A 35-year-old otherwise healthy adult presents with acute bacterial sinusitis. Which organism is the most common cause of acute bacterial rhinosinusitis in adults?
- A Haemophilus influenzae
- B Streptococcus pneumoniae ✓
- C Moraxella catarrhalis
- D Staphylococcus aureus
Correct answer: B. Streptococcus pneumoniae
Explanation
Streptococcus pneumoniae is the most common organism causing acute bacterial rhinosinusitis in adults, followed by Haemophilus influenzae and Moraxella catarrhalis. Staphylococcus aureus and anaerobes are more commonly associated with odontogenic sinusitis. This knowledge guides empiric antibiotic choice, with amoxicillin-clavulanate being first line.
Reference: Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, 9th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.